The Nature of Changes in Haematological Parameters in Patients With COVID-19

RELEVANCE: In the first half of 2020, reports appeared in the medical press about the presence of signs of multi-organ damage when a person is infected with COVID-19. It was suggested that hemoglobinopathies, hypoxia, and iron overload of parenchymal organ cells play an additional role in the pathogenesis of the disease. Based on these concepts and hypotheses, a system of pathogenetic therapy is formed. Clinical studies have not yet confirmed a number of hypotheses. To clarify them, additional laboratory tests are required. PURPOSE AND OBJECTIVES: Taking into account the available literature data and the lack of clinical data, we set the task in the study to study peripheral blood parameters and their dynamics in patients with COVID-19 who were treated with a diagnosis of viral pneumonia in a Moscow city hospital in the period April-June 2020. MATERIALS AND METHODS: All 206 patients were treated in the 3rd department (Head of MD Sokolova N. A.), including 82 men and 124 women aged from 26 to 97 years (mean age 56.8±6.1 years), 197 were discharged from the hospital, 6 were transferred to the intensive care unit, where they died, 3 died in the department. The study of peripheral blood and the calculation of the leukocyte formula were performed on the "Cobas Micro" and "Advia-21-20" analyzers (Simens, Germany). Biochemical studies were performed on a Getpremier spectrophotometer Getpremier (USA). RESULTS: The number of cases of anemia in patients with COVID-19 and pneumonia, when taking into account chronic diseases that precede the development of infection, did not exceed 3-9%.In the age group of patients aged 26-60 years, the number of cases with erythrocytosis was 27% higher than the proportion of patients with reduced red blood cells, which may be a consequence of the development of reactive erythrocytosis in response to respiratory and hemic hypoxia. In 37-38% of patients, a decrease in the hemoglobin content in the red blood cell was detected, which may be a manifestation of the blockade of hemoglobin synthesis by virus structures and the cause of heavier hypoxia.In 11-12% of patients with this pathology, thrombocytopenia was detected, and in 50-60%, signs of a decrease in platelet volume were detected, possibly due to their high consumption for intravascular thrombosis in the pulmonary bloodstream and depletion of the platelet lacing process from the megakaryocyte. Most patients with COVID-19 and pneumonia were not characterized by a symptom of leukocytosis in the acute phase of the disease, except for some patients (about 20%) in the age group of 61-97 years, which may be a sign of cellular immunodeficiency. The symptom of monocytopenia was the most characteristic manifestation of changes in the granulocytic blood germ in patients, regardless of age, it was detected in 47-70% of patients, obviously reflecting the depletion of the phagocytic link of immunity, as well as lymphopenia, diagnosed in 25-52% of patients with a positive outcome of the disease. CONCLUSIONS: The data obtained indicate a combined, multicomponent pathogenic effect of the COVID-19 virus on all three sprouts of the hematopoiesis system in patients with pneumonia: with inhibition of red blood cell saturation with hemoglobin, stimulation of erythropoiesis in some of them, changes in platelet volume, with the formation of abnormal macroforms of platelets, with the absence of reactive leukocytosis to acute inflammation, and a decrease in the number of monocytic phagocytes and lymphoid cells. It is possible that some of these changes may affect the prognosis and severity of the disease.